for a cylinder head designed in 1967, then comprimised to accomadate exhaust manifolds in the engine bay with a big bend in the exhaust ports,
I feel this head is one of fords finest efforts in motorsport.
[img]http://i2.photobucket.com/albums/y40/minga-ken/4Vhead.jpg
this set have been cleaned up a little, but are the early 69 model boss 302, with the 2.33'' inlet valves. But best of all produced 581hp @ 6800rpm and never dropped till around 8000rpm due to a lack of fuel.
but as the old saying goes "horses for courses" These things are too big for the street. kenny [/img]

 

 

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File comment: 4V head 4V head.jpg [ 367.21 KiB | Viewed 198 times ]

'69 Boss 302 had 2.25" intake valves.
'70 Boss 302 changed to 2.19" in an effort to unshroud them from the chamber edge/cylinder wall.
As for the 4 meaning 4V unfortunately it does and it doesn't. Many 4 barrel 351's from XB up had the 4 cast into the corner but were in fact the 2V open chamber head which was used on all 351's from XB up.
The only real way to tell is by the size of the ports themselves or if you have them off the engine the valves will be 2.19/1.71 as apposed to 2.04/1.65 on the 2V heads....of course that assumes they are untouched because many 2V heads have had 4V valves fitted over the years. In that case port dimensions will do it for you.

I can vouch for the CHI 3V 185's. They helped push my heavy ute(3765lbs) into the high 12's in full street trim with very non-drag friendly 17" tyres and less than 5800rpm! I believe my EFI converted 2V offy port-o-sonic carb intake also didn't help the flow of these high ported CHI heads.

"Stage 1" is like a "1/4 race cam"...3/4 of it is missing!
Pete.

[quote="XR9UTE"]'69 Boss 302 had 2.25" intake valves.
'70 Boss 302 changed to 2.19" in an effort to unshroud them from the chamber edge/cylinder wall.
As for the 4 meaning 4V unfortunately it does and it doesn't. Many 4 barrel 351's from XB up had the 4 cast into the corner but were in fact the 2V open chamber head which was used on all 351's from XB up.
The only real way to tell is by the size of the ports themselves or if you have them off the engine the valves will be 2.19/1.71 as apposed to 2.04/1.65 on the 2V heads....of course that assumes they are untouched because many 2V heads have had 4V valves fitted over the years. In that case port dimensions will do it for you.

I can vouch for the CHI 3V 185's. They helped push my heavy ute(3765lbs) into the high 12's in full street trim with very non-drag friendly 17" tyres and less than 5800rpm! I believe my EFI converted 2V offy port-o-sonic carb intake also didn't help the flow of these high ported CHI heads.

"Stage 1" is like a "1/4 race cam"...3/4 of it is missing!


you can tell by removing a rocker cover, 2V heads have large cast holes where the pushrods go into the valley, 4V have small drilled holes aprox 1/2'' due to the inlet ports size, the Aussie 4V had a dot cast next to the 4 near the rocker cover where USA 4V's did not.
I don't doubt the potential of 3V alloy's, but preferance lays with yates still.

Hey Kenny,

Got any chamber side shots of those babies?

Cheers,
Pete.

I'll take some shots n' post em 2moro

Hey Kenny,

I think someone spun you some crap....those heads aren't Boss 302 items. If they were you would have plugs in the intake face where the water used to go into the 302 intake.
Check out the Jon Kasse mpeg on the CHI site;
http://www.chiheads.com/testimonials.html
He won the 2004 engine masters competition with a Cleveland/CHI combo.
His engine hit 701hp and 622lb/ft and made 500lb/ft @ 2600rpm!
The RPM limit for this comp is 6500rpm.

Cheers,
Pete.

wanna post the pix up on here?

[quote="kenny
I don't doubt the potential of 3V alloy's, but preferance lays with yates still.[/quote]

IMO as a street head nothing beats the CHI heads. Even on a windsor I would use them instead of a set of AFR's or pro topline's. You can even oreder them for a windsor with the water passeges drilled and matching manifolds for no extra cost. Yates heads are more of a hi RPM use head, like pro stock or NASCAR.